Improvement in cutters for reducing bark



W. E. NIGKERSON. Gutter for Reducing Bark.

Patented Apr-if 2,1878.

NFEIERS. FHOTO-LITHDGRAPHER. WASHINGTON. D c.

UNITED STATES PATENT ()FFIGE.

WILLIAM E. NICKERSON, OF SOMERVILLE, MASSACHUSETTS.

IMPROVEMENT IN CUTTERS FOR REDUCING BARK.

Specification forming part of Letters Patent N 0. 201,938, dated April 2, 1878; application filed December 26, 1877.

To all whom it may concern: peripheries, each alternate disk being pro- Be it known that I,'WILLIAM EMERY N IOK- vided with di 'erent kinds of teeth. The disks ERSON, of Some'rville, in the county of Middle E are made with sharp saw-teeth, as shown sex and State of Massachusetts, have invented at e c, Fig. 2. These teeth, or at least the a certain new and useful Machine for Grindmost of them, are sharpened and set like the ing Bark, of which the following is a specifiteeth of a crosscut-saw. If desirable, a few cation: of them may be made in the shape shown in My invention consists in an arrangement Fig. 4. The teeth on the alternating disks K upon the surface of a cylinder of sets of proare all formed in the shape shown in Fig. 4, jections, one set of the said projections acting and do not project so far as the teeth 0' e on as cutters, being sharpened and set similar to the disk E. teeth-in a sharp set circular saw, the other set In making up the cylinder 0, I first place upon the arbor a disk like E, next a disk like of projections surrounding the cylinder in rows alternating with the rows of the first- K, and continue, by using alternately E and K, until the Whole cylinder is made up. I

described projections. This second series of projections do not extend so far from the cylthen fasten them upon the arbor by any desirable means.

inder as the first series, and they strike the bark flatwise, scraping oil the ridges that re- This grindingcylinder acts upon the bark main between the kerfsmade by the first sein two ways: first, the saw-teeth E, which ries of projections 0r cutters proper.

As the teeth that act as scrapers on the ridges never extend in their action to the depth of the kerfs, it is evidentthat no pieces can be knocked off that are longer than the distance between the kerfs.

Figure 1 is a perspectiveview, showing a part of the grinding-cylinder. Figs. 2 and 3 represent separate disks, which, when combined in series, compose my grindingcylinder Fig. 4, detail, showing one of the scrapingteeth. Fig. 5 represents a piece of bark, a part of which has been ground away, showing the kerfs and ridges as produced by my machine.

ing ridges T T, Fig. 5 second, the scrapingteeth k k act on the ridges T T, and reduce them to small particles.

By making the disks K thicker or thinner, thus increasing or diminishing the distance between the disks E, I can regulate the thickness of the ridges T T, and thus the dimensions of the pieces to be knocked off.

I claim as my invention The combination, on the cylinder 0, of the set of kerf-forming teeth 6 e e with the ridgereducing scrapers kit k, of less projection, substantially as described, and for the purpose As all of the parts of my machine except set forth. the grinding-cylinder O are common devices, WM. E. NIOKERSON. I shall give no description of them. Witnesses:

I construct my grinding-cylinder O of a se- R. H. EDDY,

ries of sets of disks having teeth upon their JOHN R. Snow. 

